A DNA Sequencer Cheap Enough For (Some) Doctors' Offices
cylonlover writes "Until recently, DNA decoding machines — fitting in the US$500,000 to $750,000 price range — would take weeks or even months to sequence a human genome, and the whole procedure would cost $5,000 to $10,000. That could be about to change, however, as Life Technologies introduces the Benchtop Ion Proton Sequencer — a machine that may finally deliver the power of genetics into the hands of ordinary doctors thanks to its $149,000 price tag and ability to decode a human genome in one day at a cost of $1,000."
Warning--side effects may occur.
I predict that the first buyers will be University research hospitals, and the Mayo Clinic.
It needs to drop a bit more before seeing it at your local pediatrician's.
There are two unfortunate challenges that the Ion Proton approach hasn't yet solved. The first is that the steps required to get the DNA out of human cells and into the sequencer (DNA extraction and especially library preparation) are still frustratingly complex. Their OneTouch device simplifies parts of the library prep but there are still many steps that require highly skilled people doing hours to days of work.
The second major issue is that the genome is being read out in fragments of 200-400 nucleotides, then needs to be assembled. The human genome is full of repetitive regions that are much longer than 200-400nt and when one gets a sequence read from one of these regions, it's can be very difficult to determine which of the copies of the repeat region that sequence came from. Better statistical models and algorithms for genome assembly may solve this to some extent, but there are fundamental limits to what can be done with short sequence reads. Other sequencing technologies don't suffer the short read problem, Pacific Biosciences' hardware for example can read several thousand nucleotide fragments. Mate pairing strategies might be used on the Ion instrument but the library prep for these involves considerably more challenging and manual lab work.
A hundred and fifty grand doesn't sound like a whole lot of money for medical equipment.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
Doctor: "Well, it looks like you have a common cold. But let's be sure, shall we? I just got this new DNA sequencing machine. Come back tomorrow."
The next day...
Patient: "Hebho bhoctor, bhat dho I habh?"
Doctor: "Well, it looks like you have a common cold. That will be $1000."
Yes, you bring your doctor a thumb drive with 3 billion base pairs of your genome, coding for 23,000 genes. Do you know what he says?
"What am I supposed to do with that?"
Years ago, people thought that we could find Mendelian genes for all the important things in health and disease. Now it turns out that most of the important things we want to know are controlled by hundreds or thousands of genes, each of which increases the risk by 1%, sometimes less. That's for things like cholesterol, autoimmune diseases, cancer susceptibility, etc.
For the most part, your family history is a better predictor than any genome screening. Gene tests usually aren't useful unless you have a particular gene in your family and you want to find out whether you have it, like the BRCA genes for breast cancer. If your mother died of breast cancer at age 40 because of the BRCA1 gene, and you don't have the BRCA1 gene, you don't have to worry.
There are a few key puzzles we need to crack—protein dynamics, mostly—and then we'll have the ultimate acceleration method: we'll be able to simulate it all. Right now we're content with trying to sort out those challenges, and fixing the disorders we already know how to recognize. It'll keep us busy for a long time. In the interim we'll just play with increasingly clever tricks to sort out the patterns in the sequences, and catalogue lots of people so we have things to work with when the time comes.
Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
The term "junk DNA" is now only used by shoddy science journalism. We're quite comfortable with how DNA and RNA do what they do. There's a mystery about what happens on the protein side, and the question about what functional bits of RNA (called microRNA) interact with what genes is sheerly a matter of ridiculously obtuse combinatorics. Say whatever else you will about them, fat cancer research budgets have taught us a lot about the essentials.
Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
I am a biologist. Ask me questions in my journal. I'll give car/computer analogies if possible!
No need for the invite. This is Slashdot. You had us at "Samantha".
Set your phasers on "funky"!